Antiviral activity of glucosylceramides isolated from Fusarium oxysporum against Tobacco mosaic virus infection

Glucosylceramides from Cladosporium and Their Roles in Fungi–Plant Interaction

Cladosporium species are widely distributed filamentous fungi. One of the most important species is C. herbarum, which is related to infections in a variety of plants and of concern in plantations. Fungal cerebrosides, such as glucosylceramide (GlcCer), have been described as playing important roles in fungal growth and pathogenesis, but GlcCer from C. herbarum has not been characterized so far. For this reason, the present study aimed to elucidate the chemical structure of GlcCer from C. herbarum and its role in the interaction with Passiflora edulis. Mass spectrometry characterization of purified GlcCer revealed two major molecular ions, m/z 760 and m/z 774, and it reacts with monoclonal anti-GlcCer antibodies and is exposed on the fungal surface. P. edulis treatment with GlcCer induced increased levels of superoxide as well as the expression of some genes related to plant defense, such as PR3, POD, LOX and PAL. GlcCer also enhanced growth parameters, such as plant height and root weight. All these results suggest that C. herbarum GlcCer can stimulate plant defense mechanisms, which could help plants to face fungal infections.

Effects of Organic Biostimulants Added with Zeolite on Zucchini Squash Plants Infected by Tomato Leaf Curl New Delhi Virus

The use of organic substances in integrated pest management can contribute to human- and environment-safe crop production. In the present work, a combination of organic biostimulants (Fullcrhum Alert and BioVeg 500) and an inorganic corroborant (Clinogold, zeolite) was tested for the effects on the plant response to the quarantine pest tomato leaf curl New Delhi virus (ToLCNDV). Biostimulants were applied to healthy and infected greenhouse-grown zucchini plants, and the vegetative parameters and viral titer were evaluated. Although no antiviral effects were observed in terms of both virus replication and symptom expression, these biostimulants were shown to influence plant fitness. A significant increase in biomass and in leaf, flower, and fruit production was induced in both healthy and infected plants. Biostimulants also enhanced the production of metabolites commonly involved in plant response to virus infection, such as carbohydrates, phenylpropanoids and free amino acids. These results encourage new field trials to evaluate the actual productivity of infected plants after treatments and the possible application of organic biostimulants in agriculture.

Bright Side of Fusarium oxysporum: Secondary Metabolites Bioactivities and Industrial Relevance in Biotechnology and Nanotechnology

Fungi have been assured to be one of the wealthiest pools of bio-metabolites with remarkable potential for discovering new drugs. The pathogenic fungi, Fusarium oxysporum affects many valuable trees and crops all over the world, producing wilt. This fungus is a source of different enzymes that have variable industrial and biotechnological applications. Additionally, it is widely employed for the synthesis of different types of metal nanoparticles with various biotechnological, pharmaceutical, industrial, and medicinal applications. Moreover, it possesses a mysterious capacity to produce a wide array of metabolites with a broad spectrum of bioactivities such as alkaloids, jasmonates, anthranilates, cyclic peptides, cyclic depsipeptides, xanthones, quinones, and terpenoids. Therefore, this review will cover the previously reported data on F. oxysporum, especially its metabolites and their bioactivities, as well as industrial relevance in biotechnology and nanotechnology in the period from 1967 to 2021. In this work, 180 metabolites have been listed and 203 references have been cited.

Evaluation of the Effectiveness of Soil Streptomyces Isolates for Induction of Plant Resistance Against Tomato mosaic virus (ToMV)

The ability of various Streptomyces isolates obtained from soil to induce systemic resistance in tomato (Solanum lycopersicum cv. Supra) plant against Tomato mosaic virus (ToMV) was characterized in current study. Importantly, of nine Streptomyces isolates tested herein, the culture filtrate (CF) of one isolate, designated as Streptomyces ovatisporus LC597360, was the most effective. It exhibited 93.9% biocontrol efficacy and induced a significant decrease (17.6 ± 0.8%) of symptoms severity compared with infected control plants. These finding were confirmed using I-ELISA showing that ToMV concentration was significantly reduced in plants treated with S. ovatisporus LC597360 CF as compared with plants inoculated with ToMV. Moreover, treatment with CF of S. ovatisporus LC597360 not only increased activity of defense-related enzymes such as ascorbate oxidase, catalase, peroxidase, and polyphenol oxidase, but also induced plant growth promotion. The present study is the first one that demonstrates the potential of S. ovatisporus LC597360 in biocontrol of ToMV and investigated its antiviral mechanisms.